Patterns of ecological segregation among forest and woodland birds in south-eastern Australia

Richard H. LOYN
Arthur Rylah Institute for Environmental Research Department of Natural Resources & Environment, PO Box 137 Heidelberg VIC 3084 Australia

Abstract Much information has been gathered on birds of eucalypt forests and woodlands in south-eastern Australia. This was examined to assess some of the mechanisms of ecological segregation that may apply. A database was constructed of 209 species pairs (148 species from 48 genera). Most patterns resemble those reported overseas, with habitat and range featuring as major segregating mechanisms. Use of different strata and substrates was the dominant primary mechanism allowing use of identical space by congeners. Mechanisms such as specific food preferences, migration and choice of nest sites contributed but rarely as primary factors. One species pair appears to show no ecological segregation, despite co-existence in varying proportions over a large geographical range. Indiscriminate interspecific aggression is used by some species to maintain high levels of resources for themselves, in environments that can sustain such resources throughout the year. Communal breeding is a feature of those species. Implications for conservation are discussed.
Download this article.
Key words Birds, Co-existence, Ecological segregation, Eucalypts, Forests, Habitat

Comparative foraging ecology of five species of groundpouncing birds in western Australian woodlands with comments on species decline

Harry F. RECHER1, William E. DAVIS, Jr.2 and Mike C. CALVER3
1 Centre for Ecosystem Management, School of Natural Sciences, Edith Cowan University, Joondalup, W.A. 6027, Australia
2 College of General Studies, Boston University, Boston, MA 02215, USA
3 Biological Sciences, Murdoch University, Murdoch, W.A. 6150, Australia

Abstract In this paper, we compare the foraging ecology of five Australian robins(Petroica multicolor, P. goodenovi, Eopsaltria griseogularis, Microeca fascinans, and Melanodryas cucullata) in woodlands of Western Australia. Australian robins are insectivorous and obtain the greatest proportion of their prey by pouncing from a perch to the ground. Data were collected at three different sites in eucalypt (Eucalyptus)woodland and two sites in acacia (Acacia) woodland. The species differed in habitat, structure of the ground substrates where prey were taken, proportion of foraging manoeuvres used, height of foraging perches and prey-attack distances, though there were broad overlaps in all foraging dimensions. Within a site, species were more similar to each other in their foraging behaviour and selection of foraging substrates than they were to conspecific individuals occurring elsewhere. This indicates that potential foraging behaviours were very broad, and their expression is determined by the characteristics of the habitat and available prey. At all sites, robins took prey from ground substrates characterised by a mosaic of bare soil, low ground vegetation, and litter. The smallest species, P. goodenovi, used lower perches than the other robins and probably searched for small prey which it located at short distances. P. goodenovi had the widest distribution and was the most abundant of the species studied. The implications of these findings for the conservation of ground-foraging birds in Australia are discussed.
Download this article.
Key words Foraging ecology, Ground-pouncing birds, Petroicidae, Threatened species conservation, Woodlands

Heterospecific attraction among forest birds: a review

Mikko MÖNKKÖNEN and Jukka T. FORSMAN
Department of Biology, University of Oulu, POB 3000, 90014 Oulu, Finland

Abstract In this paper we review the evidence for a habitat selection process where colonizing individuals use other species presence as cues to profitable breeding sites. Our experimental studies in Fennoscandia and North America have shown that density and species richness of migrant birds breeding in the forests respond positively to experimentally augmented titmice densities. We used analytical modeling to analyze ecological conditions, which may favor a habitat selection process where later arriving individuals (colonists) use the presence of earlier established species (residents)as a cue to profitable breeding sites. We compared the fitness of two colonist strategies: colonists could either directly sample the relative quality of the patches (termed samplers) or, alternatively, they could also use residents as a cue of patch quality(cue-users). Model results suggested that cue-using strategy is more beneficial in most ecological conditions and that this may result in heterospecific attraction. Further field experiments showed that migrant individuals selected nest sites at close vicinity of nesting titmice, and bred earlier and reproduced better. We conclude that heterospecific attraction may be a common and widespread process among forest birds particularly in seasonal environments.
Download this article.
Key words Experimental studies, Habitat selection, Migrant vs. resident birds, Reproductive output, Species richness

The effect of a typhoon on the flocking and foraging behavior of tits.

Shin-Ichi SEKI and Tamotsu SATO
Kyushu Research Center, Forestry and Forest Research Institute, 4-11-16 Kurokami, Kumamoto 860-0862, Japan

Abstract A typhoon, that struck Kyushu, the southernmost of the four main islands of Japan, in September 1999, causing extensive wind damage to forests, was found to have affected the flocking and foraging behavior of Varied Parus varius and Great Tits P. major. After the typhoon had passed, the tits tended to participate in mixedspecies flocks and preferred to forage in the lower parts, rather than in the upper parts, of the trees. Also the proportion of plant products in the diet of the Varied Tit was reduced. The population and average flock size of the tits, however, remained stable even after the typhoon. The abundance of plant products as food resources remained unchanged despite severe damage to the trees, but the vegetation cover was reduced, which probably increased the predation risk. The increase of mixed-species flocking may have resulted from the increased risk of predation; mixed-species flocking is thought to increase vigilance and foraging efficiency while not increasing intraspecific competition. Changes in diet and preferred foraging sites were also consistent with the increased predation risk hypothesis. We conclude that the changes in foraging and flocking behavior after the typhoon were mainly due to the increased predation risk caused by the reduced vegetation cover.
Download this article.
Key words Foraging site, Forest disturbance, Tit, Typhoon, Winter flocking

Foraging mode shifts of four insectivorous bird species under temporally varying resource distribution in a Japanese deciduous forest

Masashi MURAKAMI
Biodiversity Group, Institute of Low Temperature Science, Hokkaido University, Sapporo, 060-0019, Japan

Abstract Temporal changes in the foraging habitat of four forest bird species and the distribution pattern of arthropod populations were investigated. The abundance and distribution of arthropods changed drastically with the season within the forest. Lepidoptera larvae were most abundant in the canopy in the first three weeks after budbreak; their numbers decreased rapidly during mid-June. In contrast, on the forest floor, the larvae were abundant from early to late June. The foraging height of the Narcissus Flycatcher Ficedula narcissina changed in parallel with the distribution pattern of Lepidoptera larvae. Three other species, the Great Tit Parus major, Marsh Tit P. palustris, and Eastern Crowned Warbler Phylloscopus coronatus, however, did not change their foraging heights; they continued to forage in the canopy. These differences are probably due to the greater preference of the flycatcher for Lepidoptera larvae compared with the other three species. The three other species switched from feeding on Lepidoptera larvae to spiders or other arthropods in mid June, when the number of Lepidoptera larvae decreased in the canopy. The results of this study suggest that the abundance and distribution of arthropods and differences in foraging tactics among bird species considerably affect avian foraging habitat. The foraging behavior of three species of forest birds revealed species-specific responses to spatiotemporal fluctuations in the distribution of resources.
Download this article.
Key words Forest bird, Foraging tactics, Lepidoptera larvae

The effects of arthropod abundance and size on the nestling diet of two Parus species

Mizuki MIZUTANI and Naoki HIJII
Laboratory of Forest Protection, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan

Abstract Feeding habits of Parus major and P. varius inhabiting coniferous plantations of Cryptomeria japonica and Larix kaempferi, each containing a small area of deciduous broad-leaved trees, were analyzed in relation to the abundance and size distribution of arthropods. In a C. japonica-dominated (CJ) area, C. japonica trees were mainly used by P. major only, while deciduous broad-leaved trees were used by both Parus species. In a L. kaempferi-dominated (LK) area, both Parus species used L. kaempferi trees and deciduous broad-leaved trees. The composition of nestling diets differed between Parus species. For prey size, the difference in the breadth was smaller and the overlap was larger between areas than between species. These results suggest that each Parus species preferred a specific size class of prey. That is, the single-prey loader P. major preferred large prey, whereas the multiple-prey loader P. varius preferred small prey. The abundance and size distribution of arthropods greatly differed among foraging microhabitats. Both Parus species selectively used foraging microhabitats according to their prey-size preference.
Download this article.
Key words Diet selection, Foraging microhabitat, Nestling diet, Parus major, Parus varius, Size preference

Prey distribution and foraging preference for tits

Teruaki HINO Akira UNNO and Shigeru NAKANO
Faculty of Agriculture, Hokkaido University, Sapporo 060-0809, Japan

Abstract We examined the abundance and distribution of prey in four different height strata and eight tree species in a temperate forest, and analyzed the influence on foraging preference by three breeding tit (Parus) species. Densities of arthropod prey for tits in canopy foliage varied with tree species but not with height. Most of them were Lepidoptera larvae. Also, interspecific differences in choice of foraging substrate were found between tree species but not in height. These results demonstrate that tree species composition is a more important habitat factor than foliage height profile for coexistence of different tit species in forests. We examined four different measures of prey abundance to find how tits chose tree species. The largest species, the Great Tit P. major, preferred the tree species with high total biomass, and the intermediate-sized Willow Tit P. montanus preferred those with high density per leaf area. Concentrated searching for prey on a few tree species with high total biomass may be a useful strategy for inflexible perch-gleaners such as P. major, and finer-scale searching on each leaf may be more practical for agile foragers such as P. montanus which often hang-glean to reach less accessible food. In spite of these differences, both species gained benefits from choosing the tree species on which they foraged most efficiently. In contrast, the smallest species, the Coal Tit P. ater, frequently foraged on food-poor tree species. Of the three tit species, P. ater was the most generalized forager, using diverse techniques on a variety of tree species and specializing at capturing small prey quickly. These foraging patterns may make it possible for the smallest species to coexist with the other tit species.
Download this article.
Key words Foraging efficiency, Foraging technique, Parus, Prey distribution, Tree species preference

The effects of food-supply on Southeast Asian forest birds

Navjot S. SODHI
Department of Biological Sciences, National University of Singapore, Blk S2, 14 Science Drive 4, Singapore 117543, Republic of Singapore

Abstract Southeast Asian forests are being lost at an alarming rate. This unprecedented deforestation is resulting in avifauna losses. Despite this, Southeast Asian avifauna remains poorly studied. A few studies measured the food-supply and correlated it with the Southeast Asian forest bird ecology. These correlative studies (qualitative as well as quantitative) show that food-supply can affect the bird diversity, abundance/density, breeding ecology, body condition, ranging behaviour and/or flocking behaviour. However, there has been no experimental study conducted to determine the effects of food-supply on the forest bird ecology. In this geographic area, exciting research avenues remain available to study the avian feeding ecology and to explore a relationship between food-supply and forest bird ecology. Descriptive, correlative as well as experimental data on these aspects are required to enhance the knowledge of avian ecology as well as for avian conservation purposes.
Download this article.
Key words Bird ecology, Food-supply, Rainforest birds, Southeast Asia, Tropics

Spotted-throat individuals of the Rufous Vanga Schetba rufa are yearling males and presumably sterile

Satoshi YAMAGISHI1, Shigeki ASAI1, Kazuhiro EGUCHI2 and Masaru WADA3
1 Department of Zoology, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
2 Department of Biology, Faculty of Science, Kyushu University, Fukuoka 812-8581, Japan
3 College of Liberal Arts and Sciences, Tokyo Medical and Dental University, Ichikawa, Chiba 272-0827, Japan

Abstract The Rufous Vanga Schetba rufa is endemic to Madagascar and lives in one-female groups. During the 1994-1999 breeding seasons, a total of 294 nestlings were banded. Among these nestlings, 51 stayed within the study area as spottedthroat individuals. In the next breeding seasons, 35 of 45 spotted-throat individuals were subsequently observed as black-throated males, and once they became blackthroated males, these individuals never reverted to the previous spotted-throat pattern. In contrast, 30 banded nestlings were recovered as yearling females with white throats, and the femaleÅfs color pattern never changed thereafter. All the spotted-throat males were helpers or floaters. All the males of one group consisting of an adult male with a black throat and two males with spotted throats were captured and sacrificed humanely. The testes were dissected from each specimen and were histologically examined. The testes of the spotted-throat males contained only spermatogonia, and no spermatids or spermatozoa were present. In contrast, the testes of the black-throated male were well-developed and contained enlarged seminiferous tubules with lumen, where numerous spermatozoa were evident. Considering these facts, spotted-throat males of this species are assumed to be sterile. We suggest that, due to their underdeveloped testes, the spotted-throat males (one-year-old males) of the Rufous Vanga are physically incapable of breeding.
Download this article.
Key words Cooperative breeding, Delayed maturation, Madagascar, Plumage, Schetba rufa

Nest-site selection of the Red-billed Leiothrix and Japanese Bush Warbler in Japan

Hitoha E. AMANO1 and Kazuhiro EGUCHI2
1 Graduate School of Social and Cultural Studies, Kyushu University, Ropponmatsu, Fukuoka 810-8560, Japan
2 Department of Biology, Faculty of Science, Kyushu University, Fukuoka 812-8581, Japan

Abstract The Red-billed Leiothrix Leiothrix lutea has been introduced from China and is rapidly increasing in deciduous broad-leaved forests of Japan. We studied nestsite characteristics and nest-site selection of this species and the Japanese Bush Warbler Cettia diphone, a sympatric native species, in southwestern Japan. Both species placed nests exclusively in bamboo thickets and on bamboo stalks. The Red-billed Leiothrix built pendulous nests in the canopy of high concealment. The Japanese Bush Warbler placed nests on the crossing of bamboo stems and selected places of high stem density. The Japanese Bush Warblers placed nests in denser vegetation than the Red-billed Leiothrix. The segregation of nesting microhabitat was also evident in both species to coexist in bamboo thickets. Existence of few inhabitants in bamboo thickets may contribute to the invasion success of the Red-billed Leiothrix.
Download this article.
Key words Cettia diphone, Introduced birds, Leiothrix lutea, Nest-site selection

Breeding bird community and mixed-species flocking in a deciduous broad-leaved forest in western Madagascar

Teruaki HINO
Kansai Research Center, Forestry and Forest Products Research Institute, Kyoto 612-0855, Japan

Abstract: The breeding bird population of a deciduous broadleaved forest in western Madagascar was censused by means of territory mapping. Despite the foliage structure being simpler, neither species richness nor density was less than those in mature temperate forests. Species diversity was higher in the western Madagascan forest owing to the higher species evenness. Tree-cavity nesters and bark foragers were few because woodpeckers, nuthatches, and tits have not colonized Madagascar. The scarcity of birds nesting on or near the forest floor may be attributable to abundance of nest-predators such as large lizards and snakes in these areas. The bird community was dominated in abundance by the members of mixed-species flocks, almost all of which forage in the canopy. Mixed-flocking can be beneficial for these birds to avoid predation by raptors, which were frequently observed in the canopy. Since most of the flock members had relatively similar territory sizes resulting in similar densities, the high species evenness in this community may have resulted from mixed-flocking by canopy-foraging species.
Download this article.
Key words Forest bird community, Madagascar, Mixed-species flocks, Predators, Species evenness

Secondary users of Great Spotted Woodpecker (Dendrocopos major) nest cavities in urban and suburban forests in Sapporo City, northern Japan

Nobuhiko KOTAKA1 and Shigeru MATSUOKA2
1
Laboratory of Animal Sociology, Faculty of Science, Osaka City University, Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
2Woodland Bioecology Group, Hokkaido Research Center, Forestry and Forest Products Research Institute, Sapporo 062-8516, Japan

Abstract: Old nest cavities excavated by Great Spotted Woodpeckers (GSW) Dendrocopos major were examined in two study areas (urban and suburban forests) in Sapporo, the capital city of Hokkaido, northern Japan. Five avian and one mammalian secondary cavity user (SCU) species occupied 47 of 101 GSW cavities inspected. The species composition differed between urban and suburban forests. Avian SCU species occupied GSW cavities more frequently in the urban than in the suburban forests. Tree Sparrows Passer montanus and Chestnut-cheeked Starlings Sturnus philippensis were the only dominant cavity breeding species in the severely fragmented urban forests. Flying Squirrels Pteromys volans were the most dominant users of GSW cavities in the suburban forests. The density of GSW cavities depends not only on natural processes but also on human activities. The suitability of the GSW cavities for certain SCU species decreases with time. To maintain the diversity of cavity-nesting wildlife in urban and suburban areas of Sapporo, preservation of existing trees with GSW cavities as well as providing suitable habitat conditions to support continued production of new cavities is essential.
Download this article.
Key words Dendrocopos major, Nest webs, Sapporo City, Secondary cavity user, Urban area

Foraging niches of introduced Red-billed Leiothrix and native species in Japan

Hitoha E. AMANO1 and Kazuhiro EGUCHI2
1 Graduate School of Social and Cultural Studies, Kyushu University, Ropponmatsu, Fukuoka 810-8560, Japan
2 Department of Biology, Faculty of Science, Kyushu University, Fukuoka 812-8581, Japan

Abstract In Kyushu, southwestern Japan, the introduced population of the Redbilled Leiothrix Leiothrix lutea has increased rapidly and its range expanded considerably since early 1980s. In order to clarify the influences of Red-billed Leiothrix on native bird species, we examined the similarities and differences in foraging patterns among species occurring in a deciduous broadleaved forest on the Ebino Plateau, during the breeding seasons from 1997 to 2000. Leiothrix foraged in a lower vegetational layer with bamboo, intermediate in height between the foraging levels of the Japanese Bush Warbler Cettia diphone and various Parus species. Foraging height, extent of foraging on deciduous trees and foraging technique were major factors best distinguishing Leiothrix from native species. Segregation of foraging niche was distinct and no apparent niche shift, due to invasion of the new species, was detected. Aerial insects tended to be more abundant just above bamboo, mainly about one meter above the canopy, than above bare ground. Thus, jumping, a specific technique used by Leiothrix, is effective for capturing aerial insects or agile invertebrates resting on leaves and twigs. Aerial insects were found to be abundant in the foraging space preferred by Leiothrix. Gleaning and hanging, techniques mainly used by native species, are suitable for capturing prey of low mobility such as Lepidoptera larvae. Probably due to morphological constraints, Parus spp. and Japanese Bush Warblers seldom foraged by jumping, indicating that they exploit quite different food resources from those utilized by Leiothrix despite their foraging spaces overlapping to some extent. In the deciduous broadleaved forests of Kyushu, an avian guild of foraging aerial insects in intermediate and lower layers of the forests is poor. Such a community may be subject to the successful invasion of the Red-billed Leiothrix into native forests.
Download this article.
Key words Ecological isolation, Foraging niche, Interspecific competition, Introduced birds, Leiothrix lutea

Tree species preferences of insectivorous birds in a Japanese deciduous forest: the effect of different foraging techniques and seasonal change of food resources

Akira UNNO
Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan

Abstract I examined the effects of arthropod abundance and of bird foraging techniques on the tree species preferences of seven insectivorous bird species in a temperate deciduous forest. It is hypothesized that bird species with a wide range of foraging techniques respond more flexibly to the spatial distribution and seasonal change of prey than those with specialized foraging techniques. This hypothesis was supported by the fact that tits, bird species with a wide range of foraging techniques, changed their techniques when foraging in tree species with different foliage structures. They also used various tree species in late summer when food requirements increased owing to the addition of nestlings and fledglings. Bird species with a narrow range of foraging techniques, such as flycatchers and white-eyes, did not change their techniques among tree species and had strong tree species preferences in all research periods.
Download this article.
Key words Foliage structure, Prey abundance, Tree species preference, Variety of foraging technique

[Short Communications (Download each article) ]

Kawakami K & Higuchi H
Bird predation by domestic cats on Hahajima Island, Bonin Islands, Japan.

Tojo H, Nakamura S & Higuchi H
Gape patches in Oriental Cuckoo Cuculus saturatus nestlings.

Brazil M
Common Raven Corvus corax at play; records from Japan.

Kawakami K & Higuchi H
The first record of cavity nesting in the Ogasawara Islands Honeyeater Apalopteron familiare on Hahajima, Bonin Islands, Japan.

Yamasaki T
Seasonal variation of plumage color in Japanese Light-vented Bulbul Pycnonotus sinensis orii in the Yaeyama Group, Southern Ryukyus. .

Ito S
Foraging areas of Short-tailed Shearwaters during their northward migration along the Pacific coast of northern Japan.

Chochi M, Niizuma Y & Takagi M
Sexual differences in the external measurements of Black-tailed Gulls breeding on Rishiri Island, Japan.

Chiba A, Murata K, Mizuno S, Honma R & Sugimori F
External features and molecular sexing of the anomalous Pintail, Anas acuta, found at Hyo-ko Waterfowl Park, Niigata Prefecture, Japan.